The state of the art in particular comprises document EP-A1-2,711,505, U.S. Pat. No. 3,621,937 and GB-A-2,488,142.
A gearbox for an aircraft turbine engine, in particular for an airplane or helicopter turbojet engine or turboprop, may consist of an accessory gearbox (AGB), which is used to drive equipment of the turbine engine, such as pumps, electricity generators, etc. The accessory gearbox transmits mechanical power originating from the turbine engine to the equipment via a kinematic chain made up of rotating elements such as pinions or rolling bearings. A gearbox for an aircraft turbine engine may also consist of a transfer gearbox (TGB), for example to kinematically connect an accessory gearbox to a turbine shaft of the turbine engine by using two transfer shafts optionally forming an angle and connected to one another by the transfer gearbox.
Such a gearbox, in particular an accessory gearbox such as a transfer gearbox, comprises a casing defining an enclosure for housing rotating elements that are lubricated by oil, this oil further being able to serve to cool the casing. The gearbox comprises at least one tubular sleeve meshing with at least one rotating element and configured to be coupled to and rotate a shaft, for example a transfer shaft or the shaft of a piece of equipment of the turbine engine. This sleeve includes a female nesting part including splines configured to cooperate with splines of a male nesting part of the shaft.
The splines of the female nesting part of the sleeve and those of the male nesting part of the shaft must be lubricated. However, this lubrication requires only a very small amount of oil. It in fact suffices to ensure an oil level in the splines to lubricate the coupling. In the current technique, a continuously operating spray nozzle is generally used to lubricate these splines. The diameter of the spray nozzle may not be too small, which means that the splines are quite often over-lubricated. This results in needless oil consumption.
Document U.S. Pat. No. 5,119,905 illustrates a specific prior art relative to an accessory gearbox in which a spray nozzle is used intermittently. The jet of oil projected by the spray nozzle passes through a hole of the sleeve, when the engine is stopped. This technology has a drawback related to the fact that the filling of an annular reservoir supplying oil to the splines only occurs when the engine is stopped. The renewal of the oil allocated to lubricating the splines therefore only occurs particularly discontinuously over time.
The present invention in particular aims to provide a simple, effective and inexpensive solution to at least part of the aforementioned problems.